1915] PALAEOZOIC FossILs FROM Hupson Bay. 75 
HURONIA INFLECTA, Sp. nov. 
Plate VI, Figure 4. 
Cf. HuRONIAE . . . Stokes. Transactions Geol. Soc., ser. II, Vol. V, pt. 3, p. 710, pl. XL, 
fig. 2, 1840. 
Cf. Huron sp., Barrande. Syst. Sil. de la Bohéme, pl. 231, fig. 2, 1866. 
Cf. ACTINOCERAS BIGSBYI, Whiteaves. Trans. Royal Soc. Can., Vol. IX, sec. IV, p. 84, 
Deke hey2) 1s0r 
This species is represented by one specimen in our collection, which 
is undoubtedly very close to that figured by Stokes and copied by 
Barrande. Both these authors have hesitated to found a species on a 
single siphuncle but the discovery of another practically identical 
specimen at quite a different locality seems to justify that action at 
the present time. 
The specimen consists of a portion of a siphuncle 85 mm. in length 
showing parts of six siphuncular rings. Nothing is known of the shell. 
The rings have a height of 15 mm. and a diameter of 45 mm.; they 
are disposed at a low angle to the axis of the siphuncle. In vertical 
section the septa are seen to extend well inward and to be in contact 
with the posterior face of the ring next orad, almost to the outer limit 
of the ring; along this line of contact there is a slight inward inflection 
of the septum. From the point where the ring parts from the septum 
behind it, it is evenly rounded and with an orad aspect. On coming 
in contact with the septum next orad, there is a sharp, tongue-like 
inflection apicad. This peculiar arrangement of rings and septa gives 
a strong forward inclination to the latter, which are only 10 mm. apart 
normal to their direction, while the actual height of a ring is 15 mm. 
The endosiphuncle is narrow and rather indistinct with an average 
diameter of 7 mm. Annular outgrowths of the endosiphuncle spring at 
a low angle, sweep gently apicad and then turn outwards in a graceful 
curve terminating near the little tongue-like inflection of the siphun- 
cular rings. From the point of origin of one of these outgrowths to its 
most posterior extension is 23 mm. Judging from the continuity of 
these structures, they appear to represent infundibuliform membranous 
or calcareous outgrowths, rather than radiating tubuli. It is of course 
likely that the membranous expansions carried tubuli, but there is no 
evidence that they penetrated the siphuncular sheath, although the 
exterior of the rings is well shown in parts of the specimen. 
Our specimen differs from that figured by Stokes only in propor- 
tions, as Stokes’ figure shows rings 20 mm. high for a width of 32 mm., 
while our specimen has rings 15 mm. high for a width of 45 mm. 
Locality—Limestone rapids, Severn river, District of Patricia, Ontario. 
Horizon—Silurian. 
No. 3108S. Royal Ontario Museum of Palaeontology. 
